1. Field of the Invention
The present invention relates generally to a motor vehicle body, and more particularly to a motor vehicle body of simple, lightweight construction having structural uni-directional fibers overwrapped in tension in order to contribute to the vehicle body stiffness.
2. Background and Summary of the Invention
As the automotive industry explores the use of plastic vehicle structures, it is desirable to provide a method for improving the body stiffness of the plastic vehicle structures without greatly increasing the amount of material and/or weight of the vehicle. The Assignee of the present application has a U.S. application entitled "Motor Vehicle Body", Ser. No. 08/892,461 which discloses a motor vehicle body which includes a left hand inner body panel, a left hand outer body panel, a right hand inner body panel, and a right hand outer body panel. The four body panels are capable of being easily and inexpensively secured together at the longitudinal mid-line of the motor vehicle body. The motor vehicle body disclosed in the above-identified application provides a vehicle body which is lightweight, low cost, and has a minimum number of parts which is easy to manufacture and assemble.
The vehicle body structure of the present invention provides a structural, uni-directional fiber over-wrap of the plastic body panels in order to greatly enhance the physical and crash characteristics of the plastic vehicle structure. The structural uni-directional fibers, which are preferably made from carbon, graphite, KEVLAR, or fiberglass are placed in tension on an injection molded, Sheet Molding Compound (SMC). The structural fiber overwrap is provided in tension and contributes to the overall vehicle structure, thus allowing a lighter vehicle understructure to be used.
According to the principles of the present invention, a vehicle body structure is provided including a vehicle body including sidewall portions, roof portions, and front and rear wall portions. The fiber overwrap is wrapped around the vehicle body in tension. According to one aspect of the present invention, the fiber overwrap is bonded to the vehicle body. The fiber overwrap can include a plurality of thermoplastic coated fibers which are heated prior to application on the vehicle body in order to slightly melt the thermoplastic materials and create the bond between the vehicle body and the fiber overwrap. As an alternative, the fiber overwrap can be bonded to the vehicle body by an adhesive.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood however that the detailed description and specific examples, while indicating preferred embodiments of the invention, are intended for purposes of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.